Calender is a pretty obscure word, and in most cases is a misspelling of Calendar. Attached is my effort to tune wordlist to only include Calender at the very high levels
tune to make calender way more obscure than common calendar
Your probably right, but modifying a source word list is not the way to go,
I am working on completely redoing how SCOWL is created, and will keep this word in find when choosing what goes in at the default spell checking level.
This issue has moved to GitHub: https://github.com/kevina/wordlist/issues/46